When you do
constructor injection, the
container will try to find the type you’ve specified (string in your case) to inject it into the object you are resolving (the LoginView in your case). If you haven’t registered that type or an instance of that type into the container, it will
try to instantiate it. Since
the constructors for string contain parameters that the container can’t resolve, it will throw an exception. So in order to inject a dependency that the container can’t construct into an object, you must already have that dependency registered.

However, if what you are trying to pass to the LoginView is only a string, construction injection might be a bit of an overkill. Dependency injection is generally useful to decouple a class from the concrete implementation of its dependencies, and to improve
testability (among other things).In this case, the implementation of string won’t change, and you can easily mock it in a test. So if you’re going to pass a simple type (string, int, etc), I would recommend you to follow a simpler approach, for
example defining ‘test’ as a property, and setting its value directly.

If you have another questions realted specifically to Unity, you could ask it in the
Unity Forums where you could get a more specific answer, as the community there deals specifically with Unity.